Pulse and Bias Synchronization Method and System

Abstract

The radio frequency (RF) generator includes an RF power source configured to output an RF power signal and a controller coupled to the RF power source. The controller is configured to generate a pulse to modulate the RF power signal of the RF power source. The pulse includes one or more state transitions. The controller is further configured to receive a synchronization signal indicative of one or more operating characteristics or parameters of the other RF generator, and to adjust at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal. Other exemplary RF generators, RF power delivery systems including the one or more RF generators, and control methods for adjusting the state transitions of the pulse to synchronize the state transition with a defined phase of the synchronization signal are also disclosed.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Patent Application No. 18 / 084,696, filed December 20, 2022, and claims the benefit of U.S. Provisional Application No. 63 / 298,825, filed January 12, 2022. The entire disclosure of the above applications is incorporated herein by reference.

[0002] The present disclosure relates to pulse and bias synchronization systems and methods.

Background Art

[0003] Plasma processing is frequently used in semiconductor manufacturing. In plasma processing, ions are accelerated by an electric field to etch material from the surface of a substrate or to deposit material on the surface of the substrate. In one basic implementation, the electric field is generated based on an RF power signal or a DC power signal generated by one or more radio frequency (RF) generators or direct current (DC) generators of a power delivery system.

[0004] The power delivery system typically includes at least two generators, such as a source generator and a bias generator. The bias generator can control plasma parameters such as ion energy. In some implementations, the bias generator can operate at a lower frequency than the source generator. For example, the bias generator can operate at 400 kHz, and the source generator can operate at 60 MHz.

[0005] The background description provided here is for the purpose of generally presenting the content of the present disclosure. The achievements of the inventors, whose current names are listed to the extent described in this background section, and aspects of this specification that may not be eligible as prior art at the time of filing are not admitted as prior art to the present disclosure, either explicitly or implicitly.

Summary of the Invention

Means for Solving the Problem

[0006] According to one aspect of the present disclosure, a radio frequency (RF) generator includes an RF power supply configured to output an RF power signal and a controller coupled to the RF power supply. The controller is configured to generate a pulse to modulate the RF power signal of the RF power supply. The pulse includes one or more state transitions. The controller is further configured to receive a synchronization signal indicating one or more operating characteristics or parameters of another RF generator and adjust at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal.

[0007] One or more computer systems can be configured to perform a particular operation or action by installing in the system software, firmware, hardware, or a combination thereof that causes the system to perform an action during operation. One or more computer programs can be configured to perform a particular operation or action by including instructions that, when executed by a data processing apparatus, cause the apparatus to perform an action. One general aspect includes a radio frequency (RF) generator. The RF generator also includes an RF power supply configured to output an RF power signal. The RF generator also includes a controller coupled to the RF power supply, the controller being configured to generate a pulse to modulate the RF power signal of the RF power supply, the generating wherein the pulse includes one or more state transitions, receive a synchronization signal indicating one or more operating characteristics or parameters of another RF generator, and adjust at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform an action of the method.

[0008] The implementation form may include one or more of the following features. An RF generator in which the synchronization signal is a square wave generated by another RF generator. The synchronization signal changes its state at the zero crossing of the RF power signal from another RF generator. The controller includes a synchronization monitoring module configured to receive the synchronization signal and generate a synchronization active signal based on a defined phase of the synchronization signal. The defined phase includes 0 degrees, 90 degrees, 120 degrees, or 180 degrees. The controller includes a pulse state latch module that communicates with the synchronization monitoring module, and the pulse state latch module receives a pulse state signal indicating a desired state transition of the pulse, and in response to receiving the synchronization active signal, based on the pulse state signal, is configured to output a synchronization pulse state signal to adjust at least one of the state transitions of the pulse. The controller includes a pulse state generator module that communicates with the pulse state latch module, and the pulse state generator module is configured to generate a pulse state signal. The controller includes an RF power control module that communicates with the pulse state latch module, and the RF power control module is configured to receive the synchronization pulse state signal and generate a control signal for controlling the pulse. The RF generator is a first RF generator, and the pulse state latch module is configured to output the synchronization pulse state signal to a second RF generator to activate the pulse shaping mode in the second RF generator. The RF power supply is configured to output an RF power signal to a matching circuit network, and the pulse state latch module is configured to output the synchronization pulse state signal to the matching circuit network to match the adjustment of the matching circuit network to the synchronization pulse state signal. The controller includes an IMD control module configured to receive the synchronization active signal and generate an intermodulation distortion (IMD) control signal based on the synchronization active signal to control the frequency of the RF power signal. The RF power supply is configured to output an RF power signal to a matching circuit network, and the controller is configured to output the synchronization active signal to the matching circuit network to control the matching circuit network. At least one of the state transitions is a first state transition, and the controller is configured to adjust a second state transition of the pulse based on the adjustment of the first state transition.The described implementation forms of the techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0009] One general aspect includes a non-transitory computer-readable medium storing processor-executable instructions for controlling an RF generator of a power system that outputs an RF power signal. The non-transitory computer-readable medium storing the processor-executable instructions also includes generating a pulse to modulate the RF power signal of the RF power supply, the pulse including one or more state transitions. The instructions also include receiving a synchronization signal indicative of one or more operating characteristics or parameters of another RF generator. The instructions also include adjusting at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform an action of the method.

[0010] The implementation form may include one or more of the following features. A non - transitory computer - readable medium storing processor - executable instructions, where the synchronization signal is a square wave generated by another RF generator. The synchronization signal changes state at the zero - crossing of the RF power signal from another RF generator. The non - transitory computer - readable medium storing processor - executable instructions may include receiving the synchronization signal and generating a synchronization active signal based on a defined phase of the synchronization signal. The non - transitory computer - readable medium storing processor - executable instructions includes receiving a pulse - state signal indicating a desired state transition of a pulse and, in response to receiving the synchronization active signal, outputting a synchronized pulse - state signal based on the pulse - state signal to adjust at least one of the state transitions of the pulse. The non - transitory computer - readable medium storing processor - executable instructions may include receiving the synchronized pulse - state signal and generating a control signal for controlling the pulse according to the synchronized pulse - state signal. The non - transitory computer - readable medium storing processor - executable instructions may include outputting the synchronized pulse - state signal to a second RF generator to activate a pulse - shaping mode in the second RF generator. The non - transitory computer - readable medium storing processor - executable instructions may include outputting the synchronized pulse - state signal to a matching circuit network to adjust the matching circuit network according to the synchronized pulse - state signal. The non - transitory computer - readable medium storing processor - executable instructions may include receiving the synchronization active signal and generating an IMD control signal based on the synchronization active signal to control the frequency of the RF power signal. The non - transitory computer - readable medium storing processor - executable instructions may include outputting the synchronization active signal to a matching circuit network to control the matching circuit network. At least one of the state transitions is a first state transition, and based on the adjustment of the first state transition, it may include adjusting a second state transition of the pulse. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer - accessible medium.

[0011] One general aspect includes a method for controlling an RF generator of a power system. The method also includes generating a pulse to modulate an RF power signal output by an RF power supply, the pulse including one or more state transitions. The method also includes receiving a synchronization signal indicative of one or more operating characteristics or parameters of another RF generator. The method also includes adjusting at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal. Other embodiments of this aspect include corresponding computer systems, devices, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the method.

[0012] Implementations may include one or more of the following features. A method in which the synchronization signal is a square wave generated by another RF generator. The synchronization signal changes state at the zero crossing of the RF power signal from another RF generator. The method may include receiving the synchronization signal and generating a synchronization active signal based on the defined phase of the synchronization signal. The method may include receiving a pulse state signal indicative of a desired state transition of the pulse and, in response to receiving the synchronization active signal, outputting a synchronized pulse state signal based on the pulse state signal to adjust at least one of the state transitions of the pulse. The method may include receiving the synchronized pulse state signal and generating a control signal for controlling the pulse in accordance with the synchronized pulse state signal. The method may include outputting the synchronized pulse state signal to a second RF generator to activate a pulse shaping mode in the second RF generator. The method may include outputting the synchronized pulse state signal to a matching circuit network to adjust the matching circuit network to the synchronized pulse state signal. The method may include receiving the synchronization active signal and generating an IMD control signal based on the synchronization active signal to control the frequency of the RF power signal. Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0013] Further applicable areas of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0014] The present disclosure will be more fully understood from the detailed description and the accompanying drawings.

Brief Description of the Drawings

[0015]

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DETAILED DESCRIPTION OF THE INVENTION

[0016] In the drawings, reference numbers may be reused to identify similar and / or identical elements.

[0017] Here, exemplary embodiments will be described in more detail with reference to the accompanying drawings.

[0018] The power system may include a DC or RF power generator or a DC or RF generator, a matching circuit network, and a load (such as a process chamber, plasma chamber, or reactor having a fixed or variable impedance). The power generator generates a DC or RF power signal, which is received by the matching circuit network or an impedance optimization controller or circuit. The matching circuit network or impedance optimization controller or circuit matches the input impedance of the matching circuit network to the characteristic impedance of the transmission line between the power generator and the matching circuit network. Impedance matching helps to maximize the amount of power transferred to the matching circuit network (the "forward power") and minimize the amount of power reflected from the matching circuit network back to the power generator (the "reverse power" or "reflected power"). The net power delivered to the plasma is called the "delivered power" and is calculated as delivered power = forward power - reflected power. When the input impedance of the matching circuit network matches the characteristic impedance of the transmission line and the generator, the forward power and the delivered power can be maximized, and the reverse power can be minimized.

[0019] In the field of power supplies or power delivery, typically, there are two methods of applying a power signal to a load. The first, more traditional method is to apply a continuous power signal to the load. In continuous mode or continuous wave mode, the continuous power signal is typically a constant DC power signal or a sinusoidal RF power signal continuously output by a power source to the load. In the continuous mode method, the power signal assumes a constant DC output or sinusoidal output, and the amplitude and / or (for an RF power signal) frequency of the power signal can be changed to vary the output power applied to the load.

[0020] A second technique for applying an electrical signal to a load involves pulsing the RF signal rather than applying a continuous RF signal to the load. In the pulse operating mode, the RF signal is modulated by a modulation signal in order to define an envelope for the modulated electrical signal. The RF signal can be, for example, a sinusoidal RF signal or other time-varying signal. The power delivered to the load is typically changed by varying the modulation signal.

[0021] In a typical power supply configuration, the output power applied to the load is determined by using sensors that measure the forward power and the reflected power, or the voltage and current of the RF signal applied to the load. A set of any of these signals is analyzed in a control loop. The analysis is typically used to determine a power value that is used to adjust the output of the power supply in order to change the power applied to the load. In a power delivery system where the load is a process chamber or other non-linear or time-varying load, changing the impedance of the load causes a corresponding change in the power applied to the load because the applied power is, in part, a function of the impedance of the load.

[0022] In systems where the manufacture of various devices depends on the introduction of power to a load to control the manufacturing process, the power is typically delivered in one of two configurations. In the first configuration, the power is capacitively coupled to the load. Such a system is called a capacitively coupled plasma (CCP) system. In the second configuration, the power is inductively coupled to the load. Such a system is typically called an inductively coupled plasma (ICP) system. Power coupling to the plasma can also be achieved by wave coupling at microwave frequencies. Such an approach typically uses an electron cyclotron resonance (ECR) or a microwave source. A helicon source is another form of wave coupling source and typically operates at RF frequencies similar to those of conventional ICP and CCP systems. The power delivery system may include at least one bias power and / or source power applied to one or more electrodes of the load. The source power typically generates a plasma, controls the plasma density, and the bias power modulates the ions in the formation of the sheath. The bias and source may share the same electrode or use separate electrodes according to various design considerations.

[0023] When a power delivery system drives a time-varying or non-linear load such as a process chamber or a plasma chamber, the power absorbed by the bulk plasma or the plasma sheath results in an ion density having a range of ion energies. One characteristic measure of the ion energy is the ion energy distribution function (IEDF). The ion energy distribution function (IEDF) can be controlled using bias power. One way to control the IEDF for a system in which multiple RF power signals are applied to a load is to vary the multiple RF signals associated by amplitude, frequency, and phase. The relative amplitudes, frequencies, and phases of the multiple RF power signals may also be associated with coefficients related to a Fourier series. The frequencies between the multiple RF power signals may be locked, and the relative phase between the multiple RF signals may also be locked. Examples of such systems can be found by reference to U.S. Patent No. 7,602,127, U.S. Patent No. 8,110,991, and U.S. Patent No. 8,395,322, all of which are assigned to the assignee of the present application and incorporated herein by reference.

[0024] Time-varying or non-linear loads can exist in various applications. In one application, a plasma processing system may also include components for plasma generation and control. One such component is a non-linear load implemented as a process chamber such as a plasma chamber or reactor. By way of example, a typical plasma chamber or reactor utilized in a plasma processing system such as for thin film manufacturing can utilize a dual power system. One power generator (source) controls plasma generation and a power generator (bias) controls ion energy. Examples of dual power systems include the systems described in U.S. Patent No. 7,602,127, U.S. Patent No. 8,110,991, and U.S. Patent No. 8,395,322, referenced above. The dual power systems described in the patents referenced above require a closed loop control system to adapt the power operation for the purpose of controlling the ion density and its corresponding ion energy distribution function (IEDF).

[0025] There are multiple techniques for controlling a process chamber such that it can be used to generate plasma. For example, in an RF power delivery system, the phase and frequency of multiple drive RF signals operating at the same or nearly the same frequency can be used to control plasma generation. For an RF driven plasma source, the periodic waveforms that affect plasma sheath dynamics, and the corresponding energies, are generally known and are controlled by the phase interactions associated with the frequency of the periodic waveforms. Another technique in an RF power delivery system involves dual frequency control. That is, two RF frequency sources operating at different frequencies are used to supply power to a plasma chamber to provide substantially independent control of the ion density and the electron density.

[0026] Other techniques utilize a broadband RF power source to drive the plasma chamber. The broadband technique presents certain challenges. One challenge is coupling the power to the electrodes. A second challenge is that the transfer function of the generated waveform with respect to the actual sheath voltage for the desired IEDF must be formulated over a wide process space to support the interaction with the material surface. In one responsive technique in an inductively coupled plasma system, controlling the power applied to the source electrode controls the plasma density, while controlling the power applied to the bias electrode modulates the ions to control the IEDF to provide etch rate control. By using the control of the source and bias electrodes, the etch rate is controlled through the density and energy of the ions.

[0027] As integrated circuits and device manufacturing continue to evolve, the power requirements for controlling the processes for manufacturing also continue to evolve. For example, in the manufacture of memory devices, the requirements regarding bias power have been continuously increasing. The increased power generates higher energy ions for faster surface interactions, thereby increasing the etching rate and directionality of the ions. In RF systems, the increased bias current sometimes comes with an increase in the number of bias power sources coupled to the plasma sheath created in the plasma chamber and requirements for lower bias frequencies. The power increase at lower bias frequencies and the increased number of bias power sources result in intermodulation distortion (IMD) radiation from sheath modulation. The IMD radiation can significantly reduce the power delivered by the source where plasma generation occurs. U.S. Patent No. 10,821,542, issued on November 3, 2020, and titled Pulse Synchronization by Monitoring Power in Another Frequency Band, which is assigned to the assignee of the present application and incorporated herein by reference, describes a method of pulse synchronization by monitoring power in another frequency band. In the referenced U.S. patent, the pulsing of a second RF generator is controlled in accordance with detecting the pulsing of a first RF generator in the second RF generator, thereby synchronizing the pulsing between the two RF generators.

[0028] FIG. 1 shows a power supply system 110. The power supply system 110 includes a pair of RF generators 112a and 112b, also called power supplies, matching circuit networks 118a and 118b, and a load 132, such as a non-linear load, which can be a plasma chamber, a process chamber, etc. In various embodiments, RF generator 112a is called a source RF generator or power supply, and matching circuit network 118a is called a source matching circuit network. Also, in various embodiments, RF generator 112b is called a bias RF generator or power supply, and matching circuit network 118b is called a bias matching circuit network. It will be understood that the components can be referred to individually or collectively using reference numbers without subscripts or prime symbols.

[0029] In various embodiments, source RF generator 112a receives control signal 130 from matching circuit network 118b or control signal 130' from bias RF generator 112b. As will be described in more detail, control signal 130 or 130' represents an input signal to source RF generator 112a that indicates one or more operating characteristics or parameters of bias RF generator 112b. In various embodiments, synchronous bias detector 134 senses the RF signal output from matching circuit network 118b to load 132 and outputs a synchronous or trigger signal 130 to source RF generator 112a. In various embodiments, instead of trigger signal 130, a synchronous or trigger signal 130' can be output from bias RF generator 112b to source RF generator 112a. The difference between trigger or synchronous signals 130, 130' can result from the effect of matching circuit network 118b that can adjust the phase between the input signal to the matching circuit network and the output signal from the matching circuit network. Signals 130, 130' include information regarding the operation of bias RF generator 112b that enables predictive responsiveness to deal with periodic variations in the impedance of load 132 caused by bias RF generator 112b in various embodiments. In the absence of control signal 130 or 130', RF generators 112a, 112b operate autonomously.

[0030] RF generators 112a, 112b each include a respective RF power supply or amplifier 114a, 114b, an RF sensor 116a, 116b, and a processor, controller, or control module 120a, 120b. The RF power supplies 114a, 114b generate respective RF power signals 122a, 122b that are output to the respective sensors 116a, 116b. The sensors 116a, 116b receive the outputs of the RF power supplies 114a, 114b and generate respective RF output signals, or RF power signals f1, f2. The sensors 116a, 116b also output signals that vary according to various parameters sensed from the load 132. The sensors 116a, 116b are shown within the respective RF generators 112a, 112b, but the RF sensors 116a, 116b can be disposed external to the RF power generators 112a, 112b. Such external sensing can occur at the output of the RF generator, at the input of an impedance matching device disposed between the RF generator and the load, or at the output of the impedance matching device (including within the impedance matching device) and the load.

[0031] Sensors 116a, 116b detect various operating parameters and output signals X and Y. Sensors 116a, 116b may include voltage sensors, current sensors, and / or directional coupler sensors. Sensors 116a, 116b can detect (i) voltage V and current I, and / or (ii) forward power P FWD output from respective power amplifiers 114a, 114b and / or RF generators 112a, 112b, and reverse or reflected power P REV received from the respective load 132 connected to respective matching networks 118a, 118b or respective sensors 116a, 116b. Voltage V, current I, forward power P FWD and reverse power P REVmay be a scaled, filtered, or scaled and filtered version of the actual voltage, current, forward power, and reverse power associated with each power supply 114a, 114b. Sensors 116a, 116b can be analog sensors, digital sensors, or a combination thereof. In a digital implementation, sensors 116a, 116b may include an analog-to-digital (A / D) converter and a signal sampling component having a corresponding sampling rate. Signals X and Y can represent either voltage V and current I, or forward (or source) power P FWD and reverse (or reflected) power P REV .

[0032] Sensors 116a, 116b generate sensor signals X, Y that are received by respective controllers or power control modules 120a, 120b. Power control modules 120a, 120b process the respective X, Y signals 124a, 126a, and 124b, 126b and generate one or more feedforward or feedback control signals 128a, 128b to respective power supplies 114a, 114b. Power supplies 114a, 114b adjust RF power signals 122a, 122b based on the received one or more feedback or feedforward control signals. In various embodiments, power control modules 120a, 120b may each control respective matching circuit networks 118a, 118b via respective control signals. Power control modules 120a, 120b may include at least any of a proportional-integral-derivative (PID) controller or subset thereof, and / or a direct digital synthesis (DDS) component, and / or various components described below in connection with the module.

[0033] In various embodiments, matching circuit network 118a and bias matching circuit network 118b can be separate components as shown in FIG. 1. Alternatively, matching circuit networks 118a, 118b can be combined. In such embodiments, RF power signals can be combined in parallel before being transmitted to load 132 (e.g., one or more electrodes of load 132).

[0034] In various embodiments, power control modules 120a, 120b are PID controllers or subsets thereof and may include functions, processes, processors, or submodules. Control signals 128a, 128b may be drive signals and may include a DC offset or rail voltage, voltage or current magnitude, frequency, and phase components. In various embodiments, feedback control signals 128a, 128b can be used as inputs to one or more control loops. In various embodiments, the plurality of control loops can include proportional-integral-derivative (PID) control loops for RF drive and rail voltage. In various embodiments, control signals 128a, 128b can be used in a multiple-input multiple-output (MIMO) control scheme. An example of an MIMO control scheme can be found by reference to U.S. Patent No. 10,546,724, issued on January 28, 2020, having the title Pulsed Bidirectional Radio Frequency Source / Load, assigned to the assignee of the present application, and incorporated herein by reference. In other embodiments, signals 128a, 128b can provide feedforward control as described in U.S. Patent No. 10,049,857, assigned to the assignee of the present application and incorporated herein by reference.

[0035] In various embodiments, the power system 110 can include a controller 120', also referred to as a processor or control module. The controller 120' may be disposed external to either or both of the RF generators 112a, 112b and may be referred to as an external or common controller 120'. In various embodiments, the controller 120' may implement one or more of the functions, processes, or algorithms described herein with respect to one or both of the controllers 120a, 120b. Thus, the controller 120' communicates with each of the RF generators 112a, 112b via a respective pair of links 136, 138 that enable the exchange of data and control signals as needed between the controller 120' and the RF generators 112a, 112b. For various embodiments, the controllers 120a, 120b, 120' can provide analysis and control, in a distributed and cooperative manner, with the RF generators 112a, 112b. In various other embodiments, the controller 120' can provide control of the RF generators 112a, 112b, eliminating the need for the respective local controllers 120a, 120b.

[0036] In various embodiments, the RF power supply 114a, the sensor 116a, the controller 120a, and the matching circuitry 118a may be referred to as a source RF power supply 114a, a source sensor 116a, a source controller 120a, and a source matching circuitry 118a. Similarly, in various embodiments, the RF power supply 114b, the sensor 116b, the controller 120b, and the matching circuitry 118b may be referred to as a bias RF power supply 114b, a bias sensor 116b, a bias controller 120b, and a bias matching circuitry 118b. In various embodiments, as described above, the source terminology refers to an RF generator that generates plasma, and the bias terminology refers to an RF generator that adjusts the plasma ion energy distribution function (IEDF). In various embodiments, the source RF power supply and the bias RF power supply operate at different frequencies. In various embodiments, the source RF power supply operates at a higher frequency than the bias RF power supply. In various other embodiments, the source RF power supply and the bias RF power supply operate at the same frequency or substantially the same frequency.

[0037] According to various embodiments, source RF generator 112a and bias RF generator 112b include a plurality of ports for communicating with the outside. Source RF generator 122a includes a pulse synchronization output port 140, a digital communication port 142, an RF output port 144, and a control signal port 160. Bias RF generator 112b includes an RF input port 148, a digital communication port 150, and a pulse synchronization input port 152. Pulse synchronization output port 140 outputs a pulse synchronization signal 154 to pulse synchronization input port 152 of bias RF generator 112b. Digital communication port 142 of source RF generator 112a and digital communication port 150 of bias RF generator 112b communicate via digital communication link 156. Control signal port 160 of source RF generator 112a receives control signals 130 and / or 130'. RF output port 144 generates an RF control signal 158 that is input to RF input port 148. In various embodiments, RF control signal 158 is substantially the same as the RF control signal that controls source RF generator 112a. In various other embodiments, RF control signal 158 is the same as the RF control signal that controls source RF generator 112a, but is phase-shifted within source RF generator 112b according to the required phase shift generated by bias RF generator 112b. Thus, in various embodiments, source RF generator 112a and bias RF generator 112b are driven by substantially the same RF control signal or by substantially the same RF control signal phase-shifted by a predetermined amount.

[0038] FIG. 2 shows a voltage versus time plot for explaining a pulse operation mode for delivering power to a load such as load 132 of FIG. 1. More specifically, FIG. 2 shows two multi-state pulses P1, P2 of a pulse signal 212 each having a plurality of states S1 to S4 and S1 to S3. In FIG. 2, an RF signal 210 is modulated by pulses P1 and P2. As shown in states S1 to S3 of P1 and states S1 to S2 of P2, when the pulse is on, the RF generator 112 outputs an RF signal 210 having an amplitude defined by the magnitude of the pulse in each state. Conversely, between state S4 of P1 and state S3 of P2, the pulse is off and the RF generator 112 does not output the RF signal 210. Pulses P1, P2 can be repeated at a constant duty cycle or a variable duty cycle, and states S1 to S4 of each pulse P1, P2 can have the same or varying amplitudes and widths. Further, the pulse signal 212 need not be embodied as a square wave as shown in FIG. 2. As a non-limiting example, the pulse 212 can be trapezoidal, triangular, or Gaussian shaped. Further, pulses P1, P2 can have a plurality of states S1, ..., Sn of varying amplitudes, durations, and shapes. States S1, ..., Sn may repeat within a fixed or variable period. As also shown in FIG. 2, the RF signal 210 operates at a frequency that varies between or within states.

[0039] Often, it is desirable to align RF power signals from RF power generators such as source RF generator 112a and bias RF generator 112b of FIG. 1. For example, by aligning the RF power signal from the bias RF generator to the RF power signal from the source RF generator, the power delivered to a load (e.g., load 132 of FIG. 1) and the ion energy associated with the load can be made more reproducible.

[0040] When pulses are used to modulate an RF power signal, synchronization between the bias RF power signal and the pulse edge may not occur. For example, a bias RF generator may provide the bias RF power signal at random or at an arbitrary phase at the pulse edge. This randomness in phase between the bias RF power signal and the pulse edge may prevent achieving reproducibility between pulses.

[0041] For example, FIG. 3 shows voltage-versus-time plots 302, 304, 306 that illustrate the randomness of the bias RF power signal. Specifically, plot 302 includes a pulse signal 308, plot 304 includes a source signal 312, and plot 306 includes bias signals 314, 316, 318. The frequencies of the bias signals 314, 316, 318 are lower than the frequency of the source signal 312. Each bias signal 314, 316, 318 corresponds to a different instance of a bias RF generator that provides power when the pulse signal 308 changes state at pulse edge 310. For example, after the pulse signal 308 changes state at pulse edge 310, a source RF generator outputs RF power represented by signal 312, and a bias RF generator outputs RF power represented by signal 314 or signal 316 or signal 318. As shown, the bias signals 314, 316, 318, and thus the RF power from the bias generator, start at random or at an arbitrary phase with respect to pulse edge 310.

[0042] In the example of FIG. 3, the state transition at pulse edge 310 occurs at the start of the pulse signal 308. In other examples, the state transition may occur within the pulse signal 308. For example, the pulse signal 308 may include a plurality of states such as states S1 to S4 in FIG. 2. In such examples, the randomness of the bias signal may occur at the start of the pulse signal 308, at one or more of the transitions between states, and the like.

[0043] The randomness of the bias RF power signal with respect to the pulse edge can be substantially eliminated by synchronizing the pulse edge with a defined phase of the bias signal. For example, at least one state transition of the pulse (e.g., the start of the pulse, transitions between states within the pulse, etc.) can be adjusted to synchronize with a defined phase of the bias RF power signal. This adjustability of the pulse ensures that one or more pulse edges occur at a particular phase of the bias. For example, the state transition can occur at the 0-degree phase, 90-degree phase, 180-degree phase, etc. of the bias. As a result of synchronizing the transition with the defined phase of the bias signal, plasma characteristics such as the power delivered to the load and the ion energy associated with the load can be made more reproducible.

[0044] Additionally, the adjustment and control of the pulse can be achieved using a controller associated with a source RF generator such as the source RF generator 112a of FIG. 1. In such an example, the controller associated with the source RF generator receives a synchronization signal indicative of the RF signal from another RF generator such as the RF bias generator 112b of FIG. 1, and can adjust at least one of the state transitions of the pulse to synchronize the transition with the defined phase of the received synchronization signal. The adjusted pulse can then be used by the source RF generator and the bias RF generator. Thus, synchronization can occur between the RF signal from the source RF generator and the RF signal from the bias RF generator, and between the pulse edge and the bias RF signal.

[0045] Figure 4 shows an exemplary implementation of an RF power delivery system 400 for synchronizing a pulse edge with a defined phase of a bias signal. Specifically, Figure 4 shows the RF power delivery system 400 as including a source RF generator 412a and a bias RF generator 412b, both of which can be as described above with respect to generators 112a, 112b of Figure 1. For example, although not shown in Figure 4, the RF generators 412a, 412b can include an RF power source, sensors, etc. to provide RF signals to a matching network, etc., as described above with respect to Figure 1.

[0046] In the example of Figure 4, the RF generators 412a, 412b include a controller, both of which can be as described above with respect to controllers 120a, 120b of Figure 1. Additionally, the controller of the bias RF generator 412b includes a synchronization generator module 478, and the controller of the source RF generator 412a includes a synchronization monitoring module 470, a pulse state generator module 472, a pulse state latch module 474, and an RF power control module 476. As shown in Figure 4, the pulse state latch module 474 communicates with the synchronization monitoring module 470, the pulse state generator module 472, and the RF power control module 476. In various embodiments, the synchronization monitoring module 470, the pulse state generator module 472, the pulse state latch module 474, and the RF power control module 476 can be embodied in a pulse edge control module within the controller.

[0047] In various embodiments, the source RF generator 412a receives a bias synchronization signal 430, as shown in Figure 4. The bias synchronization signal 430 can be similar to the control signals 130, 130' of Figure 1 in that it represents an input signal to the source RF generator 412a indicating one or more operating characteristics or parameters of the bias RF generator 412b. In various embodiments, the bias synchronization signal 430 can be regarded as a synchronization signal or a trigger signal, as described above with respect to signals 130, 130'.

[0048] In the example of FIG. 4, the bias synchronization signal 430 is a square wave of the sine wave bias signal 480 that indicates one or more operating characteristics or parameters of the bias RF generator 412b, as shown in FIG. 4. In some examples, the bias signal 480 may represent an RF power signal. The square wave signal 430 may be based on the frequency and phase of the bias signal 480. For example, the square wave signal 430 may transition states (e.g., from high to low, from low to high, switch polarities, etc.) at the zero crossings of the sine wave bias signal 480, as shown in FIG. 4.

[0049] The bias synchronization signal 430 is generated and provided from the bias RF generator 412b. Specifically, in the example of FIG. 4, the synchronization generator module 478 of the bias RF generator 412b generates the bias synchronization signal 430 (and / or the bias signal 480). In various embodiments, the synchronization generator module 478 may include, for example, a synthesizer for generating the bias synchronization signal 430 (and / or the bias signal 480). In other examples, the bias synchronization signal 430 (and / or the bias signal 480) may be generated in a matching circuit network such as the matching circuit network 118b of FIG. 1.

[0050] In various embodiments, the bias synchronization signal 430 (and / or the bias signal 480) may be another suitable signal generated by the bias RF generator 412b, the matching circuit network, and / or another suitable source. For example, the bias RF generator 412b, the matching circuit network, and / or another suitable source may generate a timing signal, a repetitive interrupt signal, a repetitive impulse signal, etc., that indicates one or more operating characteristics or parameters of the bias RF generator 412b. In some examples, the other signal source may be a source RF generator 412a, a bias RF generator 412b, or a signal generator module disposed external or internal to the matching circuit network.

[0051] In various embodiments, the controller of source RF generator 412a receives bias synchronization signal 430 and generates synchronization active signal 482 based on the defined phase of bias synchronization signal 430. Synchronization active signal 482 can be generated during each cycle of bias synchronization signal 430 (e.g., at the defined phase of each cycle of bias synchronization signal 430). For example, in FIG. 4, synchronization monitoring module 470 receives bias synchronization signal 430 from bias RF generator 412b and imposes a desired time adjustment on bias synchronization signal 430 based on the defined phase (e.g., 0 degrees, 90 degrees, 120 degrees, 180 degrees, etc.). After adjustment, synchronization monitoring module 470 generates synchronization active signal 482 for pulse state latch module 474. For example, synchronization active signal 482 can represent time-delayed bias synchronization signal 430 provided to pulse state latch module 474.

[0052] In some examples, synchronization monitoring module 470 can additionally analyze the received bias synchronization signal 430. For example, synchronization monitoring module 470 can ensure that bias synchronization signal 430 is valid and clean enough for imposing a desired time adjustment, synchronizing pulse edges with the defined phase of bias signal 480, etc.

[0053] In various embodiments, the controller of source RF generator 412a generates pulse state signal 484 to indicate the required state transitions of the pulse. For example, in FIG. 4, pulse state generator module 472 generates pulse state signal 484 for each required state transition of the pulse and provides pulse state signal 484 to pulse state latch module 474. In some examples, pulse state signal 484 can be generated according to a defined pulse rate and duty cycle, e.g., specified by a user of system 400.

[0054] As shown in FIG. 4, the pulsed state latch module 474 receives a synchronous active signal 482 and a pulsed state signal 484, and outputs a synchronous pulsed state signal 486 to the RF power control module 476 based on the pulsed state signal 484 in order to initiate a pulse transition. In various embodiments, the pulsed state latch module 474 delays outputting the synchronous pulsed state signal 486 until both the synchronous active signal 482 and the pulsed state signal 484 are received. This adjustment ensures that the pulse state change is aligned with the defined phase of the bias synchronous signal 430 (and bias signal 480).

[0055] In various embodiments, the pulsed state latch module 474 receives the pulsed state signal 484 before the synchronous active signal 482. In such embodiments, the pulsed state latch module 474 may output the synchronous pulsed state signal 486 in response to receiving the synchronous active signal 482. In other embodiments, the pulsed state latch module 474 receives the synchronous active signal 482 before the pulsed state signal 484. In such embodiments, the pulsed state latch module 474 may output the synchronous pulsed state signal 486 in response to receiving the pulsed state signal 484.

[0056] For example, the pulse state latch module 474 may first receive a pulse state signal 484 indicating a request to change the state (e.g., start a pulse, change the state within the pulse, etc.). However, the pulse state latch module 474 delays outputting the synchronous pulse state signal 486 until it receives the synchronous active signal 482 from the synchronous monitoring module 470. In other words, the pulse state latch module 474 outputs the synchronous pulse state signal 486 in response to receiving the synchronous active signal 482. Thus, the pulse state latch module 474 adjusts or delays the transition of the pulse from the requested state change to a later time based on the synchronous active signal 482. In such an example, the width of the state (e.g., one of the states S1 - S4 of pulse P1 in FIG. 2, or one of the states S1 - S3 of pulse P2 in FIG. 2) can be increased based on the adjusted or delayed transition.

[0057] In other embodiments, the pulse state latch module 474 may adjust or advance the transition of the pulse towards the previous bias cycle. For example, instead of being delayed until the next cycle, the synchronous pulse state 486 can be advanced towards the previous cycle of the bias synchronous signal 430. This can be useful when the edge of the previous bias cycle is closer to the pulse state change than the edge of the next bias cycle. For example, the synchronous active signal 482 can be provided to the pulse state latch module 474 during each cycle of the bias synchronous signal 439 (e.g., at a defined phase of each cycle of the bias synchronous signal 430). The pulse state signal 484 can be controlled such that the signal is provided to the pulse state latch module 474 earlier in time to adjust or advance the transition of the pulse towards the previous cycle of the bias synchronous signal 430. In such an example, the width of the state (e.g., one of the states S1 - S4 of pulse P1 in FIG. 2, or one of the states S1 - S3 of pulse P2 in FIG. 2) can be reduced based on the adjusted or advanced transition.

[0058] In various embodiments, knowledge of adjustments made in one state can be used to affect subsequent states. For example, if the state transitions in a pulse are adjusted (e.g., delayed, advanced, etc.), subsequent state transitions in the pulse can be adjusted as desired based on the previous state transitions. This subsequent adjustment can help prevent unnecessary additional widths in subsequent states and ensure that the desired period of the pulse is met.

[0059] For example, FIG. 5A shows a voltage-versus-time plot of a multi-state pulse P1 of a pulse signal 512. As shown, the pulse P1 of the pulse signal 512 has a plurality of states S1 to S4 for modulating an RF signal (not shown) as described herein. The pulse signal 512 is shown as including only one pulse P1, but it will be apparent that the pulse signal 512 can include multiple pulses such as repetitive pulses or non-repetitive pulses. In various embodiments, the pulse state latch module 474 of FIG. 4 can adjust the transitions of the pulse P1 of FIG. 5A to a time later than the requested state change, as described herein. For example, the pulse state latch module 474 can delay the transition between state S1 and state S2 from time t1 to time t2, thereby increasing the width of state S1. Using this knowledge of the transition adjustment, subsequent transitions can be affected. For example, the transition between state S2 and state S3 can be advanced in time (e.g., to time t3 instead of time t4) and can occur without delay (e.g., in the requested state transition) to help prevent unnecessary additional widths in state S2.

[0060] In various embodiments, the synchronous pulse state signal 486 may represent the latch pulse state signal 484. For example, the pulse state latch module 474 may be a gated D latch or another suitable latch configuration. In such an example, the pulse state signal 484 is received at an input pin, port, etc. of the pulse state latch module 474. When received, the pulse state signal 484 is latched, gated, etc. until the synchronous active signal 482 is received at an enable pin, port, etc. of the pulse state latch module 474. In response to receiving the synchronous active signal 482 at the enable pin, port, etc., the pulse state latch module 474 may copy the pulse state signal 484 at its output, allow the pulse state signal 484 to pass, etc.

[0061] As shown in FIG. 4, the RF power control module 476 receives the synchronous pulse state signal 486 to initiate a pulse transition. When the synchronous pulse state signal 486 is received, the RF power control module 476 generates a control or drive signal 488 for controlling when the pulse changes state (e.g., at an adjusted transition) to ensure alignment between the pulse edge and the defined phase of the bias signal. In some examples, the control signal 488 may be provided to drive an RF power source or amplifier (e.g., the RF power source or amplifier 114a of FIG. 1) within the source RF generator 412a.

[0062] FIG. 5B shows the sine wave bias signal 480 of FIG. 4 over time and the generated signals used in the RF power delivery system 400. For example, the signals S1, S2, S3, S4,..., Sn of FIG. 5 correspond to instances when the pulse state signal 484 of FIG. 4 is generated, and the signals, synchronized S1, synchronized S2, synchronized S3, synchronized S4,..., synchronized Sn correspond to instances when the synchronous pulse state signal 486 of FIG. 4 is generated. Although not shown, the synchronous active signal 482 of FIG. 4 may be represented in FIG. 5B as a signal at the zero crossing of the sine wave bias signal 480, or at another desired phase of the bias signal 480.

[0063] As described herein, the state transitions of the pulses (e.g., start of a pulse, transitions between states within a pulse, etc.) can be adjusted as desired to be synchronized with any suitable phase of the bias signal. For example, FIGS. 6A-6D show various plots of voltage versus time to illustrate adjusted state transitions synchronized with different defined phases of the bias signal.

[0064] Specifically, FIG. 6A shows a plot 602a including a synchronization pulse 608a, a plot 604a including a source signal 612a, and a plot 606a including a bias signal 614a. When the pulse 608a changes state at a pulse edge 610a, the source signal 612a and the bias signal 614a begin to increase. As shown, the pulse 608a changes state at a pulse edge 610a corresponding to the 0-degree phase of the bias signal 614a.

[0065] FIGS. 6B-6D show plots similar to those of FIG. 6A, but the pulses change state at pulse edges corresponding to different phases of the bias signal. For example, FIGS. 6B-6D show synchronization plots 602b, 602c, 602d including synchronization pulses 608b, 608c, 608d, plots 604b, 604c, 604d including source signals 612b, 612c, 612d, and plots 606b, 606c, 606d including bias signals 614b, 614c, 614d, respectively. As shown in FIG. 6B, the pulse 608b changes state at a pulse edge 610b corresponding to the 90-degree phase of the bias signal 614b. In FIG. 6C, the pulse 608c changes state at a pulse edge 610c corresponding to the 120-degree phase of the bias signal 614c. In FIG. 6D, the pulse 608d changes state at a pulse edge 610d corresponding to the 180-degree phase of the bias signal 614d.

[0066] In the examples of FIGS. 6A-6D, the frequencies of each bias signal 614a-d are lower than the frequencies of their corresponding source signals 612a-d. Additionally, the synchronization pulse signals 608a-d and bias signals 614a-d of FIGS. 6A-6D may correspond to the signals in FIG. 4. For example, the synchronization pulse signals 608a-d may correspond to the synchronization pulse state signal 486 generated by the pulse state latch module 474 of FIG. 4. Additionally, the bias signals 614a-d may correspond to the bias signal 480 of FIG. 4.

[0067] In various embodiments, the teachings herein may be implemented using IMD mitigation techniques. For example, the frequency of a bias RF power signal (e.g., the RF power signal f2 of FIG. 2) is generally lower than the frequency of a source RF power signal (e.g., the RF power signal f1 of FIG. 1). In particular, at higher bias powers, a lower frequency RF bias signal introduces IMD, which causes impedance variations at a load such as the load 132 of FIG. 1. U.S. Patent No. 9,947,514, issued on April 17, 2018, entitled Plasma RF Bias Cancellation System, and assigned to the assignee of the present application and incorporated herein by reference, describes various methods for IMD mitigation. In the referenced U.S. patent, IMD mitigation may be achieved, for example, by adjusting the frequency of the source RF power signal. For example, a frequency offset may be added to the source RF power signal to compensate for the expected impedance variations introduced by the bias RF power signal. The frequency offset may be pre-determined and stored in a look-up table, or the frequency offset may be determined dynamically.

[0068] FIG. 7 shows one exemplary implementation of an RF power delivery system 700 for synchronizing a pulse edge with a defined phase of a bias signal to reduce IMD. For example, the RF power delivery system 700 of FIG. 7 is implemented using the same pulse adjustment module for synchronizing a pulse edge with a defined phase of a bias signal as described above in FIG. 4. Specifically, the RF power delivery system 700 includes a source RF generator 712a and a bias RF generator 712b of FIG. 4, both of which may be as described above with respect to generators 112a, 112b of FIG. 1. The RF generator 712a includes a controller having modules 470, 472, 474, 476 of FIG. 4 and an IMD control module 790.

[0069] In the example of FIG. 7, the IMD control module 790 includes a reproduction module 792, a frequency offset module 794, and an update module 796. The reproduction module 792, the frequency offset module 794, and the update module 796 may function in a similar manner to the reproduction module, the frequency offset module, and the update module described in U.S. Patent No. 9,947,514 referenced above.

[0070] As shown in FIG. 7, the IMD control module 790 receives a synchronization active signal 482 generated by the synchronization monitoring module 470 as described above. In various embodiments, the synchronization active signal 482 is provided to the reproduction module 792 and may function as a trigger event or signal to initiate adding a frequency offset to the source RF power signal as described in U.S. Patent No. 9,947,514 referenced above. For example, when the synchronization active signal 482 changes state (e.g., from zero to one), the reproduction module 792 may start a frequency hopping pattern to adjust the frequency of the source RF power signal.

[0071] In various embodiments, the frequency hopping pattern may be initiated at each cycle. The frequency hopping pattern may be the same at each cycle or may vary from cycle to cycle. In some examples, the frequency hopping pattern may be reproduced at a particular rate each time the bias signal 480 crosses zero (e.g., a positive zero crossing). In such an example, the frequency hopping pattern may end immediately prior to the emission of the next synchronization active signal 482 (e.g., immediately prior to the next positive zero crossing). Thus, a repeating frequency pattern that is locked to the synchronization active signal 482, which is also used to adjust the pulse edges of the pulses as described herein, may be achieved.

[0072] As shown in FIG. 7, the IMD control module 790 generates an IMD control signal 798 based on the synchronization active signal 482. For example, the IMD control module 790 outputs the IMD control signal 798 to the RF power control module 476 to control the frequency of the source RF power signal based on the frequency offset in the hopping pattern. Thus, IMD reduction is achieved while synchronizing the pulse edges with the defined phase of the bias signal 480.

[0073] In other embodiments, the IMD mitigation techniques may be implemented in the matching circuitry of the RF power delivery system. For example, in some RF systems, it is desirable to increase the bias power provided to the load. This increased bias power sometimes comes with a requirement for a lower bias frequency, along with an increase in the number of bias power supplies coupled to the load. The increased power at lower bias frequencies, and the increased number of bias power supplies, results in IMD. U.S. Patent Application No. 17 / 073,709, filed October 19, 2020, entitled Intermodulation Distortion Mitigation Using Electronic Variable Capacitor, assigned to the assignee of the present application and incorporated herein by reference, describes such IMD emissions and various methods of IMD mitigation. In the referenced U.S. patent application, IMD mitigation may be achieved, for example, by controlling the capacitance or reactance across a variable capacitance or reactance within the matching circuitry.

[0074] FIG. 8 shows one exemplary implementation of an RF power delivery system 800 for synchronizing a pulse edge with a defined phase of a bias signal to mitigate IMD. For example, the RF power delivery system 800 of FIG. 8 is implemented using the same pulse adjustment module for synchronizing a pulse edge with a defined phase of a bias signal as described above in FIG. 4. Specifically, the RF power delivery system 800 includes a source RF generator 812a, the bias RF generator 412b of FIG. 4, and a matching circuitry 818. As shown, the source RF generator 812a includes a controller having the modules 470, 472, 474, 476 of FIG. 4. The source RF generator 812a, the bias RF generator 412b, and the matching circuitry 818 may be as described above with respect to the generators 112a, 112b and the matching circuitry 118a, 118b of FIG. 1. In various embodiments, the matching circuitry 818 may be implemented as a dual matching circuitry as described in U.S. Patent Application No. 17 / 073,709 referenced above.

[0075] As shown in FIG. 8, the matching circuit network 818 includes an IMD control module 890 having a reproduction module 892, a reactance or capacitance offset module 894, and an update module 896. The reproduction module 892, the reactance or capacitance offset module 894, and the update module 896 can function in a manner similar to the reproduction module, the reactance or capacitance offset module, and the update module described in U.S. patent application Ser. No. 17 / 073,709, referenced above.

[0076] In the example of FIG. 8, the IMD control module 890 receives a synchronization active signal 482 generated by the synchronization monitoring module 470 as described above. In various embodiments, the synchronization active signal 482 is provided to the reproduction module 892 and can function as a trigger event or signal to synchronize the application of a reactance that is one or both of an inductive offset or a capacitive offset (or adjustment) to the matching circuit network 818, as described in U.S. patent application Ser. No. 17 / 073,709, referenced above. For example, when the synchronization active signal 482 changes state (e.g., from zero to one), the reproduction module 892 can initiate an adjustment of the reactance or capacitance across a variable reactance or capacitor (not shown) within the matching circuit network 818. In such an example, each adjustment of the reactance or capacitance in the matching circuit network 818 can be locked to the synchronization active signal 482, which is also used to adjust the pulse edge of the pulse as described herein. By adjusting the reactance or capacitance within the matching circuit network 818, IMD can be reduced. Thus, IMD reduction is achieved while synchronizing the pulse edge with the defined phase of the bias signal 480, as described herein.

[0077] Figures 9 and 10 show various voltage-versus-time plots 900, 1000 that exhibit adjusted state transitions synchronized with different defined phases of the bias signal while also achieving IMD reduction. For example, plots 900, 1000 include synchronous pulse state signals 902, 1002, signals 904, 1004 representing the reflected power of a 60 MHz source generator (e.g., source RF generators 712a, 812a of FIGS. 7 and 8), signals 906a, 1006a representing the forward power of a 400 kHz bias generator (e.g., bias RF generator 412b of FIGS. 7 and 8), and synchronous signals 906b, 1006b. In various embodiments, the synchronous pulse state signals 902, 1002 of FIGS. 9 and 10 may correspond to the synchronous pulse state signals of FIGS. 7 and 8, and the synchronous signals 906b, 1006b of FIGS. 9 and 10 may correspond to the bias synchronous signals of FIGS. 7 and 8.

[0078] As shown in FIGS. 9 and 10, the state transitions of the pulses are adjusted to be synchronized with different defined phases of the synchronous signals 906b, 1006b. For example, in FIG. 9, the synchronous pulse state signal 902 changes state at a pulse edge corresponding to approximately 180 degrees phase of the synchronous signal 906b. In FIG. 10, the synchronous pulse state signal 1002 changes state at a pulse edge corresponding to approximately 90 degrees phase of the synchronous signal 1006b.

[0079] In various embodiments, one or more signals generated in one RF generator, such as RF generator 412a of FIG. 4, may be provided to one or more other RF generators, one or more components, etc. within the RF power delivery system. For example, one RF generator, such as a source RF generator, may provide a feedback signal to one or more other RF generators, such as a bias RF generator, to control the other generators. In such an example, the RF generator providing the feedback signal is considered the leader, and the RF generator receiving the feedback signal is considered the follower. In other examples, one RF generator, such as a source RF generator, may provide a feedback signal to one or more components, such as a matching circuit network, as further described below.

[0080] For example, FIG. 11 shows one exemplary implementation of an RF power delivery system 1100 for synchronizing a pulse edge with a defined phase of a bias signal. The RF power delivery system 1100 of FIG. 11 is implemented using the same pulse adjustment module for synchronizing a pulse edge with a defined phase of a bias signal as described above with respect to FIG. 4. Specifically, the RF power delivery system 1100 includes a source RF generator 1112a, a bias RF generator 412b of FIG. 4, and one or more other RF generators 1112n. As shown, the source RF generator 1112a includes a controller having modules 470, 472, 474, 476 of FIG. 4. The RF generators 412b, 1112a, 1112n may be as described above with respect to the generators 112a, 112b of FIG. 1.

[0081] In the example of FIG. 11, the synchronous pulse state signal 486 is fed back to the RF generators 412b, 1112n. More specifically, the pulse state latch module 474 of the source RF generator 1112a generates the synchronous pulse state signal 486 and outputs it to the RF generators 412b, 1112n. The RF generator 412b and / or the RF generator 1112n may utilize the synchronous pulse state signal 486 in various ways. For example, the synchronous pulse state signal 486 may instruct the RF generator 412b and / or the RF generator 1112n when to operate, when to change the pulse state, when to start moving the supplied power to the next state, when to start moving the frequency to the next state, etc.

[0082] In some examples, the synchronization pulse state signal 486 may be provided to the RF generator 412b and / or the RF generator 1112n to activate the pulse shaping mode in the RF generator 412b and / or the RF generator 1112n. For example, U.S. Patent No. 10,049,857, issued on August 14, 2018, and titled Adaptive Periodic Waveform Controller, which is assigned to the assignee of the present application and incorporated herein by reference, describes various modules for shaping pulses based on one or more set values. These set values may include, for example, a forward power set value generated based on a repeating pattern. In the referenced U.S. patent, a trigger signal may be generated to initiate a pulse shaping method based on one or more set values.

[0083] In various implementations, the RF generator 412b and / or the RF generator 1112n may include a controller having one or more modules for shaping pulses based on one or more set values, as described in U.S. Patent No. 10,049,857 referenced above. In such an example, the synchronization pulse state signal 486 may function as a trigger signal to initiate a pulse shaping method based on one or more set values, as described in U.S. Patent No. 10,049,857.

[0084] As shown in FIG. 11, the RF power delivery system 1100 further includes one or more components 1118n. The component 1118n may include any suitable component that receives a control signal. For example, the component 1118n may include one or more matching circuit networks, as described above with respect to the matching circuit networks 118a, 118b of FIG. 1.

[0085] In the example of FIG. 11, the synchronization pulse state signal 486 is fed back to component 1118n. More specifically, the pulse state latch module 474 of the source RF generator 1112a generates the synchronization pulse state signal 486 and outputs it to component 1118n. In an example where at least one of components 1118n is a matching circuit network such as an electronic matching circuit network, the synchronization pulse state signal 486 may instruct the matching circuit network to initiate its adjustment process. In such an example, the adjustment of the matching circuit network may be aligned with the synchronization pulse state signal 486.

[0086] For example, FIG. 12 shows one exemplary implementation of an RF power delivery system 1200 for synchronizing a pulse edge with a defined phase of a bias signal. The RF power delivery system 1200 of FIG. 12 is implemented using the same pulse adjustment module for synchronizing a pulse edge with a defined phase of a bias signal as described above in FIG. 4. Specifically, the RF power delivery system 1200 includes a source RF generator 1212a, the bias RF generator 412b of FIG. 4, and a matching circuit network 1218. As shown, the source RF generator 1212a includes a controller having modules 470, 472, 474, 476 of FIG. 4. Additionally, the RF generators 412b, 1112a and the matching circuit network 1218 may be those described above with respect to the generators 112a, 112b and the matching circuit networks 118a, 118b of FIG. 1.

[0087] In the example of FIG. 12, the synchronization pulse state signal 486 is provided to the matching circuit network 1218. More specifically, the pulse state latch module 474 of the source RF generator 1212a generates the synchronization pulse state signal 486 and outputs it to the matching circuit network 1218. In such an example, the matching circuit network 1218 may utilize the synchronization pulse state signal 486 as a signal to initiate the adjustment. In other words, the synchronization pulse state signal 486 may instruct the matching circuit network 1218 when to initiate the adjustment in order to ensure that the adjustment of the matching circuit network 1218 is aligned with the synchronization pulse state signal 486.

[0088] The systems disclosed herein can be operated using a number of methods including various control system methods shown in FIGS. 1, 4, 7, 8, 11, and 12. FIG. 13 shows an exemplary flowchart of one of the operations mainly described with respect to the implementation of FIG. 4. The following operations are mainly described with respect to the implementation of FIG. 4, but the operations can be easily modified for application to other implementations of the present disclosure. The operations may be executed repeatedly. The following operations are mainly shown and described as being executed sequentially, but one or more of the following operations may be executed while one or more of the other operations are being executed.

[0089] FIG. 13 shows, for example, a flowchart 1300 of a control system for performing pulse edge adjustment control for the power delivery system 400 of FIG. 4. Control starts and proceeds to blocks 1302, 1306 that are independent of each other. In block 1302, the control generates a pulse state signal (e.g., pulse state signal 484 of FIG. 4) indicating a request to change the pulse state (e.g., start a pulse, transition between states within a pulse, etc.). In some examples, the pulse state signal is generated by a pulse state generator module such as pulse state generator module 472 of FIG. 4. In block 1306, the control determines whether a bias synchronization signal (e.g., bias synchronization signal 430 of FIG. 4) has been received. Blocks 1302, 1306 can be executed at the same or different times. For example, the control can determine whether the bias synchronization signal is received in block 1306 before, after, or at the same time as the control generates the pulse state signal in block 1302.

[0090] When a bias synchronization signal is received at block 1306, control proceeds to block 1310. Otherwise, control returns to block 1306 to determine again whether the bias synchronization signal has been received. At block 1310, control generates a synchronization active signal (e.g., the synchronization active signal 482 in FIG. 4) based on the received bias synchronization signal. For example, control may generate the synchronization active signal based on a defined phase of the bias synchronization signal. In such an example, after receiving the bias synchronization signal, control may impose a desired time delay on the bias synchronization signal based on a defined phase (e.g., 0 degrees, 90 degrees, 120 degrees, 180 degrees, etc.). After the time delay, control generates the synchronization active signal.

[0091] After control generates the synchronization active signal at block 1310, control proceeds to block 1314. At block 1314, control transmits the synchronization active signal to a pulse state latch module such as the pulse state latch module 474 in FIG. 4. Next, control returns to block 1306 to determine again whether the bias synchronization signal has been received.

[0092] After control generates the pulse state signal at block 1302, control proceeds to block 1318. At block 1318, control transmits the pulse state signal to the pulse state latch module. Thus, both the pulse state signal and the synchronization active signal are provided to the pulse state latch module, but not necessarily at the same time.

[0093] At block 1322, control determines whether the pulse state latch module has received the pulse state signal. If so, control proceeds to block 1326. Otherwise, control returns to block 1322. In other examples, if it is determined that the pulse state latch module has not received the pulse state signal, control may return to block 1302 or block 1318.

[0094] In block 1326, the control determines whether the pulse state latch module has received a synchronous active signal. If so, the control proceeds to block 1330. Otherwise, the control returns to block 1326. In block 1330, the control uses the pulse state latch module to generate a synchronous pulse state signal for starting the transition of the pulse. In this way, the pulse state latch module delays starting the transition of the pulse until both the synchronous active signal and the pulse state signal are received. For example, the pulse state latch module may first receive a pulse state signal indicating a request to change the state. However, the pulse state latch module delays generating, outputting, etc. the synchronous pulse state signal until it also receives the synchronous active signal. Thus, the pulse state latch module adjusts the transition of the pulse to a later time from the requested state change (based on the pulse state signal) based on the synchronous active signal. This adjustment ensures that the state change of the pulse is aligned with the defined phase of the bias synchronous signal.

[0095] After the control generates the synchronous pulse state signal to start the transition of the pulse in block 1330, the control returns to generate again the pulse state signal indicating a request to change the pulse state.

[0096] Figure 14 incorporates various exemplary components of the previous figure into the control module. Specifically, Figure 14 shows a control module 1400 as including a power generation module section and a pulse edge adjustment module section. The power generation module section includes an RF amplitude control module 1404 and an RF frequency control module 1408. The RF amplitude control module 1404 includes a playback module 1416, an amplitude adjustment module 1420, and an amplitude update module 1424. The RF frequency control module 1408 includes a playback module 1428, a frequency adjustment module 1432, and a frequency update module 1436. The pulse edge adjustment module section includes a pulse edge control module 1412 having a pulsed state generator module 1440, a synchronization monitoring module 1444, a pulsed state latch module 1448, and an RF power control module 1452. In various examples, the RF power control module 1452 may be at least partially incorporated within the power generation module section. In various embodiments, the control module 1400 includes one or more processors that execute code associated with the module section or modules 1400, 1404, 1408, 1412, 1416, 1420, 1424, 1428, 1432, 1436, 1440, 1444, 1448, 1452.

[0097] At least the operation of the module section or modules 1400, 1412, 1440, 1444, 1448, and 1452 has been described above with respect to the exemplary method of Figure 14. For further defined structures of the controllers and modules described herein, refer to the descriptions and the flowchart of Figure 14 provided above, as well as the definition provided below for the term "module".

[0098] In this specification, for example, a specific implementation form of a controller for performing pulse edge adjustment control is described, but it will be clear that any suitable control implementation form can be used. For example, in various embodiments, any one of the controllers disclosed in this specification may implement a multi-input multi-output (MIMO) control system, a single-input single-output (SISO) control system, etc. Additionally, in various embodiments, any one of the controllers disclosed in this specification may implement artificial intelligence (AI) control techniques, machine learning (ML) techniques, etc.

[0099] Using any one of the pulse edge adjustment implementation forms and related control techniques described in this specification can result in various advantages. For example, the pulse edge adjustment implementation forms and related control techniques disclosed in this specification guarantee the synchronization between the pulse edge of a pulse and the defined phase of a bias signal by adjusting the state transition of the pulse (e.g., the start of the pulse, the transition between states within the pulse, etc.). Such synchronization eliminates the randomness of the bias RF power signal with respect to the pulse edge in the pulse and guarantees that plasma characteristics such as the power delivered to the load and the ion energy related to the load are more reproducible. Additionally, the synchronization can occur between the RF signal from the source and the bias RF generator.

[0100] Additionally, in many cases, the pulse rate and duty cycle that define the desired pulse transition time can be specified by the user. The pulse edge adjustment implementation forms and related techniques disclosed in this specification guarantee that the actual pulse transition occurs near this desired pulse transition time and is synchronized with the defined phase of the bias.

[0101] Furthermore, the pulse edge adjustment implementation forms and related techniques disclosed in this specification may provide reduction of reflected power, improvement of the reliability of the power generator, reduction of IMD at the pulse edge, and improvement of the reproducibility of pulse energy.

[0102] The foregoing description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or its use. The broad teachings of the disclosure can be implemented in a variety of forms. Accordingly, while this disclosure includes particular examples, upon review of the drawings, specification, and following claims, other modifications will be apparent, and the true scope of the disclosure should not be so limited. In the specification and claims, one or more steps within a method may be performed in a different order (or simultaneously) without changing the principles of the disclosure. Similarly, one or more instructions stored within a non-transitory computer-readable medium may be executed in a different order (or simultaneously) without changing the principles of the disclosure. Unless otherwise indicated, the numbering or other labeling of instructions or method steps is for convenient reference only and does not indicate a fixed order.

[0103] Furthermore, while each of the embodiments has been described above as having particular features, any one or more of these features described with respect to any embodiment of the disclosure may be implemented in and / or combined with any of the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more of the embodiments remain within the scope of the disclosure.

[0104] Spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.) are described using various terms including "connected", "engaged", "coupled", "adjacent", "in contact with", "on top of", "above", "below", and "disposed". Unless explicitly stated to be "direct", when a relationship between a first element and a second element is described in the above disclosure, the relationship can be a direct relationship with no other intervening elements between the first element and the second element, but can also be an indirect relationship with one or more intervening elements (spatially or functionally) between the first element and the second element.

[0105] The phrase "at least one of A, B, and C" should be interpreted to mean the logic (A OR B OR C) using non-exclusive logical OR, and should not be interpreted to mean "at least one A, at least one B, and at least one C". The term "set" does not necessarily exclude the empty set; in other words, in some situations, a "set" may have zero elements. The term "non-empty" set can be used to indicate the exclusion of the empty set; in other words, a non-empty set always has one or more elements. The term "subset" does not necessarily require a proper subset; in other words, a "subset" of a first set may have the same extent (may be equal) as the first set. Further, the term "subset" does not necessarily exclude the empty set; in some situations, a "subset" may have zero elements.

[0106] In the figure, the direction of the arrow indicated by the arrowhead generally indicates the flow of information (such as data or instructions) important for the illustration. For example, if element A and element B exchange various information and the information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This one-way arrow does not mean that no other information is transmitted from element B to element A. Further, regarding the information transmitted from element A to element B, element B may transmit a request or an acknowledgment of receipt for that information to element A.

[0107] In the present application including the following definitions, the term "module" can be replaced by the term "controller" or the term "circuit". In the present application, the term "controller" can be replaced by the term "module". The term "module" refers to an application-specific integrated circuit (ASIC), a digital, analog, or analog / digital hybrid discrete circuit, a digital, analog, or analog / digital hybrid integrated circuit, a combinational logic circuit, a field-programmable gate array (FPGA), processor hardware that executes code (shared, dedicated, or grouped), memory hardware that stores code executed by the processor hardware (shared, dedicated, or grouped), other suitable hardware components that provide the described functions, or some or all of the combinations of the above, such as in a system-on-chip, or a part thereof, or may include it.

[0108] The module may include one or more interface circuits. In some examples, the interface circuit may implement a wired interface or a wireless interface to connect to a local area network (LAN) or a wireless personal area network (WPAN). Examples of LANs are the Institute of Electrical and Electronics Engineers (IEEE) Standard 802.11-2020 (also known as the WIFI wireless networking standard), and the IEEE Standard 802.3-2018 (also known as the Ethernet wired networking standard). Examples of WPANs are the IEEE Standard 802.15.4 (including the ZIGBEE standard from the ZigBee Alliance), and the BLUETOOTH wireless networking standard (including core specification versions 3.0, 4.0, 4.1, 4.2, 5.0, and 5.1 from the Bluetooth Special Interest Group (SIG)).

[0109] The module may communicate with other modules using the interface circuit. Although the module may be shown in this disclosure as communicating logically directly with other modules, in various implementations, the module may actually communicate via a communication system. The communication system includes physical and / or virtual networking devices such as hubs, switches, routers, and gateways. In some implementations, the communication system connects to or traverses a wide area network (WAN) such as the Internet. For example, the communication system may include multiple LANs connected to each other via the Internet or a point-to-point dedicated line using technologies including Multiprotocol Label Switching (MPLS) and Virtual Private Network (VPN).

[0110] In various implementations, the functionality of a module may be distributed among multiple modules connected via a communication system. For example, multiple modules may implement the same functionality that is distributed by a load balancing system. In a further example, the functionality of a module may be divided between a server (also known as remote or cloud) module and a client (or user) module. For example, a client module may include a native application or a web application that runs on a client device and communicates with the server module over a network.

[0111] Some or all of the hardware functionality of a module may be defined using a hardware description language such as IEEE standard 1364-2005 (commonly referred to as "Verilog") and IEEE standard 1076-2008 (commonly referred to as "VHDL"). A hardware description language may be used to manufacture and / or program a hardware circuit. In some implementations, some or all of the functionality of a module may be defined by a language such as IEEE 1666-2005 (commonly referred to as "SystemC") that includes both the code described below and a hardware description.

[0112] The term code as used above may include software, firmware, and / or microcode and may refer to a program, routine, function, class, data structure, and / or object. Shared processor hardware includes a single microprocessor that executes some or all of the code from multiple modules. Group processor hardware includes a microprocessor that, in combination with additional microprocessors, executes some or all of the code from one or more modules. References to multiple microprocessors include multiple microprocessors on separate dies, multiple microprocessors on a single die, multiple cores of a single microprocessor, multiple threads of a single microprocessor, or a combination of the above.

[0113] Memory hardware can also store data either together with or separately from the code. Shared memory hardware includes a single memory device that stores some or all of the code from multiple modules. An example of shared memory hardware can be a level I cache on or near a microprocessor die that can store code from multiple modules. Another example of shared memory hardware can be a persistent storage such as a solid state drive (SSD) that can store code from multiple modules. Group memory hardware includes a memory device that stores some or all of the code from one or more modules in combination with other memory devices. An example of group memory hardware can be a storage area network (SAN) that can store the code of a particular module across multiple physical devices. Another example of group memory hardware can be the random access memory of each of a set of servers that stores the code of a particular module in combination.

[0114] The term memory hardware is a subset of the term computer-readable medium. The term computer-readable medium as used herein does not include transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave), and thus the term computer-readable medium is considered tangible and non-transitory. Non-limiting examples of non-transitory computer-readable media are non-volatile memory devices (such as flash memory devices, erasable programmable read-only memory devices, or mask read-only memory devices), volatile memory devices (such as static random access memory devices or dynamic random access memory devices), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray Discs).

[0115] The devices and methods described in this application may be implemented partially or fully by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. Such devices and methods may be described as computerized devices and computerized methods. The functional blocks and flowchart elements described above function as software specifications that can be converted into a computer program by the routine work of an experienced technician or programmer.

[0116] A computer program includes processor-executable instructions stored on at least one non-transitory computer-readable medium. The computer program may also include, or be dependent on, stored data. The computer program may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, and the like.

[0117] A computer program can include (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (eXtensible Markup Language), or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a computer, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, the source code can be described using syntax from languages including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, JavaScript®, HTML5 (Hypertext Markup Language 5th revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB®, SIMULINK®, and Python®.

Explanation of Signs

[0118] 110 Power supply system 112 RF generator 112a RF generator, source RF generator, RF power generator, generator 112b RF generator, bias RF generator, RF power generator, generator 114a RF power supply or amplifier, RF power supply, power supply, source RF power supply 114b RF power supply or amplifier, RF power supply, power supply, bias RF power supply 116a RF sensor, sensor, source sensor 116b RF sensor, sensor, bias sensor 118a Integrated circuit network, source integrated circuit network, integrated circuit 118b integrated circuit network, bias integration circuit network, integrated circuit 120' controller, external or common controller 120a processor, controller, or control module, controller or power control module, power control module, local controller, source controller 120b processor, controller, or control module, controller or power control module, power control module, local controller, bias controller 122a RF power signal 122b RF power signal 124a X signal 124b X signal 126a Y signal 126b Y signal 128a feedforward or feedback control signal, control signal, feedback control signal, signal 128b feedforward or feedback control signal, control signal, feedback control signal, signal 130 control signal, synchronization or trigger signal, trigger signal, trigger or synchronization signal, signal 130' control signal, synchronization or trigger signal, trigger or synchronization signal, signal 132 load 134 synchronization bias detector 136 link 138 link 140 pulse synchronization output port 142 digital communication port 144 RF output port 148 RF input port 150 digital communication port 152 pulse synchronization input port 154 pulse synchronization signal 156 digital communication link 158 RF control signal 160 control signal port 210 RF signal 212 pulse signal, pulse 302 Plot 304 Plot 306 Plot 308 Pulse Signal 310 Pulse Edge 312 Source Signal, Signal 314 Bias Signal, Signal 316 Bias Signal, Signal 318 Bias Signal, Signal 400 RF Power Delivery System, Power Delivery System 412a Source RF Generator, RF Generator 412b Bias RF Generator, RF Generator 430 Bias Synchronization Signal, Square Wave Signal 470 Synchronization Monitoring Module, Module 472 Pulse State Generator Module, Module 474 Pulse State Latch Module, Module 476 RF Power Control Module, Module 478 Synchronization Generator Module 480 Sinusoidal Bias Signal, Bias Signal 482 Synchronization Active Signal 484 Pulse State Signal, Latch Pulse State Signal 486 Synchronization Pulse State Signal 488 Control or Drive Signal, Control Signal 512 Pulse Signal 602a Plot 602b Plot 602c Plot 602d Plot 604a Plot 604b Plot 604c Plot 604d Plot 606a Plot 606b Plot 606c Plot 606d Plot 608a Synchronization Pulse 608b Synchronization Pulse 608c Synchronization Pulse 608d Synchronization Pulse 610a Pulse Edge 610b Pulse Edge 610c Pulse Edge 610d Pulse Edge 612a Source Signal 612b Source Signal 612c Source Signal 612d Source Signal 614a Bias Signal 614b Bias Signal 614c Bias Signal 614d Bias Signal 700 RF Power Delivery System 712a Source RF Generator 790 IMD Control Module 792 Reproduction Module 794 Frequency Offset Module 796 Update Module 798 IMD Control Signal 800 RF Power Delivery System 812a Source RF Generator 818 Integrated Circuit Network 890 IMD Control Module 892 Reproduction Module 894 Reactance or Capacitance Offset Module 896 Update Module 900 Plot 902 Synchronization Pulse Status Signal 904 Signal 906a Signal 906b Synchronization Signal 1000 Plot 1002 Synchronization Pulse Status Signal 1004 Signal 1006a Signal 1006b Synchronization Signal 1100 RF Power Delivery System 1112a Source RF Generator 1112n RF Generator 1118n components 1200 RF power delivery system 1212a source RF generator 1218 integrated circuit network 1400 control module 1404 RF amplitude control module 1408 RF frequency control module 1412 pulse edge control module 1416 playback module 1420 amplitude adjustment module 1424 amplitude update module 1428 playback module 1432 frequency adjustment module 1436 frequency update module 1440 pulse state generator module 1444 synchronization monitoring module 1448 pulse state latch module 1452 RF power control module

Claims

Claim 1 A radio frequency (RF) generator comprising: an RF power supply configured to output an RF power signal; a controller coupled to the RF power supply, the controller being configured to: generate a pulse to modulate the RF power signal of the RF power supply, the pulse including one or more state transitions; receive a synchronization signal indicative of one or more operating characteristics or parameters of another RF generator; adjust at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal; and a controller configured to perform the above operations; and an RF generator comprising the above components. Claim 2 The RF generator according to claim 1, wherein the synchronization signal is a square wave generated by the other RF generator. Claim 3 The RF generator according to claim 2, wherein the synchronization signal changes state at a zero crossing of an RF power signal from the other RF generator. Claim 4 The RF generator according to claim 1, wherein the controller includes a synchronization monitoring module configured to receive the synchronization signal and generate a synchronization active signal based on the defined phase of the synchronization signal. Claim 5 The RF generator according to claim 4, wherein the defined phase includes 0 degrees, 90 degrees, 120 degrees, or 180 degrees. Claim 6 The RF generator according to claim 4, wherein the controller includes a pulse state latch module communicating with the synchronization monitoring module, the pulse state latch module receiving a pulse state signal indicative of a desired state transition of the pulse, and in response to receiving the synchronization active signal, outputting a synchronization pulse state signal based on the pulse state signal to adjust at least one of the state transitions of the pulse. Claim 7 The RF generator according to claim 6, wherein the controller includes a pulse state generator module communicating with the pulse state latch module, the pulse state generator module being configured to generate the pulse state signal. Claim 8 The RF generator according to claim 6, wherein the controller includes an RF power control module communicating with the pulse state latch module, the RF power control module being configured to receive the synchronization pulse state signal and generate a control signal for controlling the pulse.

9. The RF generator is a first RF generator, and the pulsed state latch module is configured to output the synchronization pulsed state signal to the second RF generator in order to activate a pulse shaping mode in the second RF generator, the RF generator according to claim 6.

10. The RF power supply is configured to output the RF power signal to a matching circuit network, and the pulsed state latch module is configured to output the synchronization pulsed state signal to the matching circuit network in order to adjust the matching circuit network according to the synchronization pulsed state signal, the RF generator according to claim 6.

11. The controller includes an IMD control module configured to receive the synchronization active signal and generate an intermodulation distortion (IMD) control signal based on the synchronization active signal in order to control the frequency of the RF power signal, the RF generator according to claim 4.

12. The RF power supply is configured to output the RF power signal to a matching circuit network, and the controller is configured to output the synchronization active signal to the matching circuit network in order to control the matching circuit network, the RF generator according to claim 4.

13. At least one of the state transitions is a first state transition, and the controller is configured to adjust a second state transition of the pulse based on an adjustment of the first state transition, the RF generator according to claim 1.

14. A non-transitory computer-readable medium storing processor-executable instructions for controlling an RF generator of a power supply system that outputs a radio frequency (RF) power signal, the RF generator including an RF power supply, the processor-executable instructions being generating a pulse to modulate the RF power signal of the RF power supply, the pulse including one or more state transitions, the generating; receiving a synchronization signal indicating one or more operating characteristics or parameters of another RF generator; adjusting at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal and including a non-transitory computer-readable medium storing processor-executable instructions.

15. A non-transitory computer-readable medium storing processor-executable instructions according to claim 14, wherein the synchronization signal is a square wave generated by the other RF generator.

16. A non-transitory computer-readable medium storing processor-executable instructions according to claim 15, wherein the synchronization signal changes state at the zero crossing of the RF power signal from the other RF generator.

17. A non-transitory computer-readable medium storing processor-executable instructions according to claim 14, further comprising receiving the synchronization signal and generating a synchronization active signal based on the defined phase of the synchronization signal.

18. A non-transitory computer-readable medium storing processor-executable instructions according to claim 17, further comprising receiving a pulse state signal indicating a desired state transition of the pulse and outputting a synchronized pulse state signal based on the pulse state signal to adjust at least one of the state transitions of the pulse in response to receiving the synchronization active signal.

19. A non-transitory computer-readable medium storing processor-executable instructions according to claim 18, further comprising receiving the synchronized pulse state signal and generating a control signal for controlling the pulse according to the synchronized pulse state signal.

20. A non-transitory computer-readable medium storing processor-executable instructions according to claim 19, further comprising outputting the synchronized pulse state signal to the second RF generator to activate a pulse shaping mode in the second RF generator.

21. A non-transitory computer-readable medium storing processor-executable instructions according to claim 19, further comprising outputting the synchronized pulse state signal to the matching circuit network to adjust the matching circuit network according to the synchronized pulse state signal.

22. A non-transitory computer-readable medium storing processor-executable instructions according to claim 17, further comprising receiving the synchronization active signal and generating an IMD control signal based on the synchronization active signal to control the frequency of the RF power signal.

23. A non-transitory computer-readable medium storing processor-executable instructions according to claim 17, further comprising outputting the synchronous active signal to an integrated circuit network to control the integrated circuit network.

24. A non-transitory computer-readable medium storing processor-executable instructions according to claim 14, further comprising adjusting a second state transition of the pulse based on an adjustment of the at least one of the state transitions being a first state transition.

25. A method for controlling a radio frequency (RF) generator of a power system, comprising: generating a pulse to modulate an RF power signal output by an RF power source, the pulse including one or more state transitions; receiving a synchronization signal indicating one or more operating characteristics or parameters of another RF generator; adjusting at least one of the state transitions of the pulse to synchronize the state transition with a defined phase of the received synchronization signal. A method comprising the steps of:

26. The method according to claim 25, wherein the synchronization signal is a square wave generated by the other RF generator.

27. The method according to claim 26, wherein the synchronization signal changes state at a zero crossing of an RF power signal from the other RF generator.

28. The method according to claim 25, further comprising receiving the synchronization signal and generating a synchronous active signal based on the defined phase of the synchronization signal.

29. The method according to claim 28, further comprising receiving a pulse state signal indicating a desired state transition of the pulse, and outputting a synchronous pulse state signal based on the pulse state signal to adjust at least one of the state transitions of the pulse in response to receiving the synchronous active signal.

30. The method according to claim 29, further comprising receiving the synchronous pulse state signal and generating a control signal for controlling the pulse according to the synchronous pulse state signal.

31. The method according to claim 30, further comprising outputting the synchronous pulse state signal to a second RF generator to activate a pulse shaping mode in the second RF generator.

32. The method according to claim 30, further comprising the step of outputting the synchronization pulse state signal to the integrated circuit network in order to adjust the integrated circuit network according to the synchronization pulse state signal.

33. The method according to claim 28, further comprising the step of receiving the synchronization active signal and the step of generating an IMD control signal based on the synchronization active signal to control the frequency of the RF power signal.

34. The method according to claim 28, further comprising the step of outputting the synchronization active signal to the integrated circuit network to control the integrated circuit network.

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